Closed
Description
Dave Syer opened SPR-15939 and commented
When I run a basic Spring Boot app using Java 9 (and classpath, etc. - normal Java 8 command line), I see red WARN messages from the JDK. It seems they are caused by something in CGLib. Harmless but users will not like it.
$ java -cp target/demo-0.0.1-SNAPSHOT.jar:$CP com.example.demo.DemoApplication
. ____ _ __ _ _
/\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
\\/ ___)| |_)| | | | | || (_| | ) ) ) )
' |____| .__|_| |_|_| |_\__, | / / / /
=========|_|==============|___/=/_/_/_/
:: Spring Boot :: (v2.0.0.BUILD-SNAPSHOT)
2017-09-08 10:58:33.782 INFO 17229 --- [ main] com.example.demo.DemoApplication : Starting DemoApplication v0.0.1-SNAPSHOT on tower with PID 17229 (/home/dsyer/dev/demo/workspace/demo/target/demo-0.0.1-SNAPSHOT.jar started by dsyer in /home/dsyer/dev/demo/workspace/demo)
2017-09-08 10:58:33.784 INFO 17229 --- [ main] com.example.demo.DemoApplication : No active profile set, falling back to default profiles: default
2017-09-08 10:58:33.814 INFO 17229 --- [ main] ConfigServletWebServerApplicationContext : Refreshing org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext@1224144a: startup date [Fri Sep 08 10:58:33 BST 2017]; root of context hierarchy
WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by org.springframework.cglib.core.ReflectUtils$1 (file:/home/dsyer/.m2/repository/org/springframework/spring-core/5.0.0.BUILD-SNAPSHOT/spring-core-5.0.0.BUILD-SNAPSHOT.jar) to method java.lang.ClassLoader.defineClass(java.lang.String,byte[],int,int,java.security.ProtectionDomain)
WARNING: Please consider reporting this to the maintainers of org.springframework.cglib.core.ReflectUtils$1
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release
2017-09-08 10:58:34.803 INFO 17229 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 8080 (http)
...
Apparently, this is because --illegal-access=permit is the default in Java 9, so you can switch it off with --illegal-access=deny, but it's awkward to have a default setting that emits a warning.
If I run the app using modules, the error also goes away, which is interesting:
$ java -p target/demo-0.0.1-SNAPSHOT.jar:$CP --add-modules ALL-DEFAULT -m demo/com.example.demo.DemoApplication --endpoints.default.web.enabled=true
. ____ _ __ _ _
/\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
\\/ ___)| |_)| | | | | || (_| | ) ) ) )
' |____| .__|_| |_|_| |_\__, | / / / /
=========|_|==============|___/=/_/_/_/
:: Spring Boot ::
2017-09-08 10:52:23.903 INFO 16567 --- [ main] com.example.demo.DemoApplication : Starting DemoApplication on tower with PID 16567 (/home/dsyer/dev/demo/workspace/demo/target/demo-0.0.1-SNAPSHOT.jar started by dsyer in /home/dsyer/dev/demo/workspace/demo)
2017-09-08 10:52:23.905 INFO 16567 --- [ main] com.example.demo.DemoApplication : No active profile set, falling back to default profiles: default
2017-09-08 10:52:23.930 INFO 16567 --- [ main] ConfigServletWebServerApplicationContext : Refreshing org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext@4f4c4b1a: startup date [Fri Sep 08 10:52:23 BST 2017]; root of context hierarchy
2017-09-08 10:52:24.716 INFO 16567 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 8080 (http)
2017-09-08 10:52:24.7
...
Affects: 5.0 RC3
Issue Links:
- MethodHandles.Lookup.defineClass for CGLIB class definition purposes [SPR-15859] #20414 MethodHandles.Lookup.defineClass for CGLIB class definition purposes ("duplicates")